The present invention relates generally to apparatus and methods for closing and/or sealing openings into body lumens, and more particularly to apparatus and methods for delivering a vascular closure element for closing an iatrogenic puncture in a blood vessel formed during a diagnostic or therapeutic procedure.
Catheterization and interventional procedures, such as angioplasty or stenting, generally are performed by inserting a hollow needle through a patient""s skin and muscle tissue into the vascular system. A guide wire may then be passed through the needle lumen into the patient""s blood vessel accessed by the needle. The needle may be removed, and an introducer sheath may be advanced over the guide wire into the vessel. A catheter may then be advanced through a lumen of the introducer sheath and over the guide wire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate introduction of various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure.
Upon completion of the procedure, the catheter and introducer sheath may be removed, leaving a puncture site in the vessel wall. External pressure may be applied to the puncture site until clotting and wound sealing occur. This procedure, however, may be time consuming and expensive, requiring as much as an hour of a physician""s or nurse""s time. It is also uncomfortable for the patient, and requires that the patient remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.
Various apparatus have been suggested for percutaneously sealing a vascular puncture by occluding the puncture site. For example, U.S. Pat. Nos. 5,192,302 and 5,222,974, issued to Kensey et al., describe the use of a biodegradable plug that may be delivered through an introducer sheath into a puncture site. When deployed, the plug may seal the vessel and provide hemostasis. Such devices, however, may be difficult to position properly with respect to the vessel, which may be particularly significant since it is generally undesirable to expose the plug material, e.g., collagen, within the bloodstream, where it may float downstream and risk causing an embolism.
Another technique has been suggested that involves percutaneously suturing the puncture site, such as that disclosed in U.S. Pat. No. 5,304,184, issued to Hathaway et al. Percutaneous suturing devices, however, may require significant skill by the user, and may be mechanically complex and expensive to manufacture.
To facilitate positioning devices that are percutaneously inserted into a blood vessel, xe2x80x9cbackbleedxe2x80x9d indicators have been suggested. For example, U.S. Pat. No. 4,317,445, issued to Robinson, discloses a flashback chamber on a first end of a cannula that communicates with a port on a second end. The second end is percutaneously introduced into a patient until the port enters the vessel, whereupon blood, under normal blood pressure, may advance along the cannula and enter the flashback chamber, thereby providing a visual indication that the vessel has been entered. This reference, however, does not discuss vascular wound closure, but is merely directed to an introducer device. In contrast, U.S. Pat. No. 5,676,974, issued to Kensey et al., discloses a back bleed lumen intended to facilitate positioning of a biodegradable plug within a puncture site. This device, however, requires that an anchor of the plug be positioned within the vessel, and therefore, may increase the risk of over-advancement of the plug itself into the vessel.
Alternatively, U.S. Pat. No. 5,674,231, issued to Green et al., discloses a deployable loop that may be advanced through a sheath into a vessel. The loop is intended to resiliently expand to engage the inner wall of the vessel, thereby facilitating holding the sheath in a desired location with respect to the vessel. The loop may also provide a support for facilitating the deployment and deflection of a surgical clip against the vessel wall. Such a device, however, may risk engagement between the loop and the surgical clip, thereby preventing the loop from a being withdrawn from the vessel.
Accordingly, apparatus and methods for vascular puncture closure that are simpler to manufacture and/or use, or that overcome the disadvantages of known devices would be considered useful.
The present invention is directed to apparatus and methods for providing access into a blood vessel or other body lumen from an incision or puncture, and/or for delivering a closure element for closing the incision.
In accordance with one aspect of the present invention, an apparatus is provided that includes a sheath having proximal and distal ends, the distal end having a size and shape for insertion into a body lumen. The distal end includes first and second ports therein, the second port being disposed at a more distal location than the first port. An obturator is disposed within the sheath, the obturator including a distal region having a size for sealingly engaging an interior surface of the sheath. The obturator includes first and second openings in the distal region, the first and second openings being alignable with the first and second ports in the sheath. First and second lumens extend distally from the proximal end of at least one of the sheath and the obturator, the first and second lumens communicating with the first and second openings, respectively. One or more of the lumens may be located within the wall of one of the sheath or obturator, or may be defined by a region between the sheath and obturator.
In addition, the apparatus may include a closure element slidably disposed on an exterior of the sheath, the closure element configured for engaging tissue adjacent an opening into a body lumen for closing the opening. Preferably, a housing is slidably disposed on the exterior of the sheath, the housing configured for releasably holding the closure element. The housing may be actuable from a proximal end of the sheath for advancing the closure element distally during deployment of the closure element.
In a preferred embodiment, the first and second ports are axially aligned with one another. A marker may then be provided on the proximal end of the tubular sheath, the marker having a let predetermined peripheral orientation about the sheath for identifying the peripheral location of the first and second ports.
During use, the obturator may be inserted into the sheath, and the first and second ports may be aligned with the first and second openings when the obturator is fully inserted into the sheath. The obturator and the sheath may include cooperating detents for securing the obturator axially with respect to the sheath when the obturator is fully inserted into the sheath. Alternatively, the first opening may be aligned with the first port when the obturator is inserted a first distance into the sheath, and the second opening may be aligned with the second port when the obturator is inserted a second distance into the sheath.
In one embodiment, the first and second lumens may extend within the obturator between its proximal end and the first and second openings, respectively. Alternatively, the second lumen may extend axially through the obturator, and the first lumen may be defined by an annular lumen between the obturator and the sheath.
In accordance with another aspect of the present invention, an apparatus is provided for delivering a vascular closure element into engagement with tissue adjacent an opening into a body lumen. The apparatus includes a sheath having proximal and distal ends and an exterior surface. The sheath includes an interior surface defining a first lumen extending between the proximal and distal ends, and one or more ports in the distal end communicating with the first lumen. A housing is slidably disposed on the exterior of the sheath, the housing being configured for releasably holding a closure element. The housing is actuable from a proximal end of the sheath for advancing the closure element distally during deployment of the closure element.
An obturator is insertable into the first lumen of the sheath, the obturator including a distal region configured for sealingly engaging the interior surface of the sheath, thereby defining an annular region between the obturator and the sheath proximal to the distal region. The annular region may communicate with the one or more ports when the obturator is fully inserted into the sheath. A backbleed port may be provided on the proximal end of the sheath, the backbleed port communicating with the first lumen.
In accordance with yet another aspect of the present invention, an apparatus is provided for introduction into an opening in a wall of a body lumen. The apparatus includes a sheath having proximal and distal ends, the distal end having a size and shape for insertion into a body lumen. The distal end of the sheath includes first and second ports therein, the second port being disposed at a more distal location than the first port. The sheath may include a clip housing, a peripheral marker or other features, similar to the embodiments described above.
An obturator is disposed within the sheath, the obturator including a distal region having a size for sealingly engaging an inner surface of the sheath. The obturator is movable with respect to the sheath for selectively opening and closing the first and second side ports to permit fluid flow therethrough to the proximal end of the sheath. In one embodiment, the obturator at least partially defines a first lumen extending from the proximal end of the sheath towards the distal region of the obturator. The obturator preferably includes a region for selectively sealing the first and second ports in the sheath, whereby only one of the first and second ports communicates with the first lumen.
Preferably, the first lumen is defined between the obturator and the inner surface of the sheath. The obturator may include a second lumen therein having an inlet proximal to the distal region of the obturator and a piston for sealingly engaging the inner surface of the sheath. The piston may be located proximal to the inlet, whereby the second lumen communicates with the second side port when the obturator is disposed at a first position, and the first lumen communicates with the first side port when the obturator is disposed at a second position. The obturator may movable axially or rotated with respect to the sheath between the first and second positions.